gamma-Butyrolactone (γ-butyrolactone or GBL) is a hygroscopic colorless oily liquid with a weak characteristic
odorAn odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also called smells, which can refer to both pleasant and unpleasant odors...
and is soluble in water. GBL is a common
solventA solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution.The most common solvent in everyday life is water. Most other commonly-used solvents are organic chemicals. These are called organic solvents...
and
reagentA reagent or reactant is a substance or compound consumed during a chemical reaction. Solvents and catalysts, although they are involved in the reaction, are usually not referred to as reactants....
in
chemistryChemistry is the science concerned with the composition, behavior, structure, and properties of matter, as well as the changes it undergoes during chemical reactions...
and is used as an
aroma compoundAn aroma compound, also known as odorant, aroma, fragrance or flavor, is a chemical compound that has a smell or odor...
, as a stain remover, as a superglue remover, as a
paint stripperPaint stripper, or paint remover, is the generic name given to solvent mixtures designed to remove paint and other finishes and also to clean the underlying surface. The principal active ingredient is usually dichloromethane...
, and as a
solventA solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution.The most common solvent in everyday life is water. Most other commonly-used solvents are organic chemicals. These are called organic solvents...
in some wet aluminium electrolytic capacitors.
GBL has been found in extracts from samples of unadulterated wines.
gamma-Butyrolactone (γ-butyrolactone or GBL) is a hygroscopic colorless oily liquid with a weak characteristic
odorAn odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also called smells, which can refer to both pleasant and unpleasant odors...
and is soluble in water. GBL is a common
solventA solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution.The most common solvent in everyday life is water. Most other commonly-used solvents are organic chemicals. These are called organic solvents...
and
reagentA reagent or reactant is a substance or compound consumed during a chemical reaction. Solvents and catalysts, although they are involved in the reaction, are usually not referred to as reactants....
in
chemistryChemistry is the science concerned with the composition, behavior, structure, and properties of matter, as well as the changes it undergoes during chemical reactions...
and is used as an
aroma compoundAn aroma compound, also known as odorant, aroma, fragrance or flavor, is a chemical compound that has a smell or odor...
, as a stain remover, as a superglue remover, as a
paint stripperPaint stripper, or paint remover, is the generic name given to solvent mixtures designed to remove paint and other finishes and also to clean the underlying surface. The principal active ingredient is usually dichloromethane...
, and as a
solventA solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution.The most common solvent in everyday life is water. Most other commonly-used solvents are organic chemicals. These are called organic solvents...
in some wet aluminium electrolytic capacitors.
Occurrence
GBL has been found in extracts from samples of unadulterated wines. This finding indicates that GBL is a naturally occurring component in some wines and may be present in similar products. The concentration detected was approximately 5 μg/mL and was easily observed using a simple extraction technique followed by
GC/MSGas chromatography-mass spectrometry is a method that combines the features of gas-liquid chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC-MS include drug detection, fire investigation, environmental analysis, explosives investigation,...
analysis.
Preparation
GBL can be synthesized from
gamma-hydroxybutyric acidγ-Hydroxybutyric acid , also known as 4-hydroxybutanoic acid and sodium oxybate, is a naturally-occurring substance found in the central nervous system, wine, beef, small citrus fruits, and almost all animals in small amounts. It is also a neuroprotective therapeutic nutrient that is...
(GHB) by removal of water or by distillation from such a mixture. It may also be obtained via oxidation of
tetrahydrofuranTetrahydrofuran is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. This heterocyclic compound has the chemical formula 4O. As one of the most polar ethers with a wide liquid range, it is a useful solvent. Its main use is however as a...
(THF). One such process, which affords GBL in yields of up to 80%, utilises
bromineBromine , is a chemical element with the symbol Br and atomic number 35. A halogen element, bromine is a reddish-brown volatile liquid at standard room temperature that is intermediate in reactivity between chlorine and iodine. Bromine vapors are corrosive and toxic. Approximately 556,000 metric...
generated
in situIn situ is a Latin phrase meaning in the place. It is used in many different contexts.-Aerospace:In the aerospace industry, equipment on board aircraft must be tested in situ, or in place, to confirm everything functions properly as a system. Individually, each piece may work but interference from...
from an aqueous solution of sodium bromateSodium bromate is a strong oxidant, mainly used in continuous or batch dyeing processes involving sulfur or vat dyes and as a hair-permagent, chemical agent, or gold solvent in gold mines when used with sodium bromide....
and potassium hydrogen sulfatePotassium bisulfate is the potassium salt of bisulfate anion, with the molecular formula KHSO4. This compound is commonly used in the conversion of tartrates to bitartrates in wine...
.
Chemistry
GBL is a lactoneIn chemistry, a lactone is a cyclic ester which can be seen as the condensation product of an alcohol group -OH and a carboxylic acid group -COOH in the same molecule...
. It is hydrolyzedHydrolysis is a chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions, which may go on to participate in further reactions. It is the type of reaction that is used to break down certain polymers, especially those made by step-growth polymerization...
under basic conditions, for example in a sodium hydroxideSodium hydroxide , also known as lye and caustic soda, is a caustic metallic base. It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 1998 was around...
solutionIn chemistry, a solution is a homogeneous mixture composed of two or more substances. In such a mixture, a solute is dissolved in another substance, known as a solvent. Gases may dissolve in liquids, for example, carbon dioxide or oxygen in water. Liquids may dissolve in other liquids. Gases can...
into sodium gamma
-hydroxybutyrate, the sodiumSodium is a metallic element with a symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals within "group 1"...
salt of gamma-hydroxybutyric acid. Under acidic conditions it forms an
equilibriumIn a chemical process, chemical equilibrium is the state in which the chemical activities or concentrations of the reactants and products have no net change over time. Usually, this would be the state that results when the forward chemical process proceeds at the same rate as their reverse reaction...
mixture of both compounds.
Pharmacology
GBL is not active in its own right, its mechanism of action stems from its identity as a
prodrugA prodrug is a pharmacological substance that is administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and excretion optimization...
of GHB.
The hypnotic effect of GHB is enhanced by combination with alcohol. A 2003 rat study showed that GBL in combination with ethanol showed a potentiated hypnotic effect, as the sleep-timing measure was longer than both of the individual components combined.
Pharmacokinetics
GBL is rapidly converted into GHB by lactonase enzymes found in the blood. GBL is more lipophilic (fat soluble) than GHB, and so is absorbed faster and has higher
bioavailabilityIn pharmacology, bioavailability is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered intravenously, its bioavailability is 100%...
; the paradox is that this can mean that GBL has a faster onset of effects than GHB itself, even though it is a prodrug. The levels of lactonase enzyme can vary between individuals, and GBL is not active in its own right, so people who have never tried GBL before may have delayed or fewer effects than expected; however, once someone has taken GBL a few times, the production of lactonase enzymes is increased and he/she will feel the effects as normal.
Because of these pharmacokinetic differences, GBL tends to be more potent and faster-acting than GHB, but has a shorter duration; whereas the related compound
1,4-butanediol1,4-Butanediol is the organic compound with the formula HOCH2CH2CH2CH2OH. This colorless viscous liquid is derived from butane by placement of alcohol groups at each end of the chain...
(1,4-B) tends to be slightly less potent, slower to take effect but longer-acting than GHB.
Use as a nutritional supplement
Due to its property of being a
prodrugA prodrug is a pharmacological substance that is administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and excretion optimization...
of
GHBγ-Hydroxybutyric acid , also known as 4-hydroxybutanoic acid and sodium oxybate, is a naturally-occurring substance found in the central nervous system, wine, beef, small citrus fruits, and almost all animals in small amounts. It is also a neuroprotective therapeutic nutrient that is...
, GBL was sold as a nutritional supplement after the scheduling of GHB, under the names Revivarant and Renewtrient in the U.S. at least until the end of 1999.
GBL (as well as GHB), when taken internally in therapeutic doses without the presence of other drugs (especially alcohol, as mixing the two can be fatal), has been shown to elevate growth hormone levels in humans to at least 5 times the baseline.
Recreational use
GBL is a
prodrugA prodrug is a pharmacological substance that is administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and excretion optimization...
of
GHBγ-Hydroxybutyric acid , also known as 4-hydroxybutanoic acid and sodium oxybate, is a naturally-occurring substance found in the central nervous system, wine, beef, small citrus fruits, and almost all animals in small amounts. It is also a neuroprotective therapeutic nutrient that is...
. To bypass GHB restriction laws, home synthesis kits were introduced to transform GBL and/or 1,4-B into GHB. GBL can also be used as a recreational drug by itself.
GBL overdose can cause severe sickness,
comaIn medicine, a coma is a profound state of unconsciousness. A comatose person cannot be awakened, fails to respond normally to pain or light, does not have sleep-wake cycles, and does not take voluntary actions....
and
deathDeath is the termination of the biological functions that define a living organism. It refers to both a particular event and to the condition that results thereby. The true nature of the latter has for millennia been a central concern of the world's religious traditions and of philosophical...
.
Metabolism takes place in stomach and blood plasma. GBL is longer acting and has a shorter onset than GHB. Otherwise, effects are similar to GHB, although weight for weight it is significantly more powerful, meaning dosage must be lowered accordingly. If taken undiluted by mouth, GBL can cause esophageal and gastro-intestinal irritation. It is possible for oral ingestion of GBL to cause nausea and other similar problems, possibly more so than with GHB.
Excessive use
GHB (gamma hydroxybutyrate) and GBL (gamma butyrolactone) are substances which are often used as recreational drugs. GHB has two effects, at low doses it has a euphoric effect (which is why it is sometimes referred to as liquid ecstasy). At higher doses it acts like a sedative and can make the user unconscious very quickly.
Addictiveness
If used frequently it can cause physical dependency. Currently not much is known about GHB/GBL dependency syndrome. It can be characterized as “round the clock” use, where users may have to dose from as frequently as every forty minutes to an hour. This is because withdrawal symptoms can begin as quickly as 40 minutes from the last dose. There appears to be a temporal pattern of withdrawal symptoms which include extreme anxiety, sleeplessness, feeling shaky, confusion, nausea and vomiting. In addition further withdrawal symptoms may include auditory and visual hallucinations, delirium and psychosis. These symptoms can be mistaken for psychosis as GHB/GBL can be difficult to detect in the system. Withdrawal from GHB/GBL is similar to withdrawal from severe alcohol dependency.
Withdrawal symptoms seem to increasingly begin quicker if GHB/GBL is used "round the clock" for an extended period of time, like several years.
Dangers from withdrawal symptoms: As with chronic alcohol addiction, withdrawal from GHB/GBL dependency should be done under medical supervision and preferably on an inpatient basis. It can be dangerous to suddenly stop taking GHB/GBL. In addition care should be taken when using GHB/GBL with other substances including alcohol as this could easily result in accidental overdose.
Withdrawal times: varies depending on a range of factors but is usually between 5–10 days. Some users who have taken GHB/GBL for several years reportedly feel withdrawal symptoms for up to six months after they stop taking it, although not as intense as the initial symptoms.
The recommended treatment; is to stabilise symptoms of anxiety and psychotic symptoms. High doses of diazepam are usually indicated to control psychotic agitation. Patients with GHB/GBL dependency have a high tolerance to the sedating effects of benzodiazepines and require large doses similar to those for alcohol dependency. Patients also require frequent monitoring of their symptoms.
Long term recovery: early reports are that recovery from dependant use is promising after detoxification, although this is an area which needs more research.
Clients with GHB/GBL dependency should contact a doctor for medical advice. Under no circumstances should excessive users stop dosing themselves until they've seen a doctor or medical professional.
Dose
A millilitre of pure GBL metabolizes to roughly 1.6g of GHB, so doses are measured in the single milliliter range, either taken all at once or sipped over the course of a night. GBL has a distinctive taste and odour, described as stale water or burnt plastic.
Legal status of GBL
Canada:
GBL is a Controlled Substance under Schedule VI of the "Controlled Drugs and Substances Act" in Canada. Schedule VI of the "Controlled Drugs and Substances Act" requires vendors to collect information regarding purchases of GBL. It is not illegal for an individual to possess GBL in Canada.
United Kingdom:
GBL is an unclassified drug in the United Kingdom, but the UK Government has announced that it will be classified class C, with a prison term of up to two years for possession and 14 years for dealing, by the end of 2009.
Sweden: GBL is not classified as a drug but as a health-endangering substance.
See also
- gamma-Hydroxybutyrate (GHB)
- 1,4-Butanediol
1,4-Butanediol is the organic compound with the formula HOCH2CH2CH2CH2OH. This colorless viscous liquid is derived from butane by placement of alcohol groups at each end of the chain...
(1,4-B)
External links
- Erowid on GBL
- BBC News story: The paint stripper drug that kills, October 7, 2005.
- “All About GHB," a NIDA Neuroscience Consortium and OSPC “Cutting Edge” colloquium (27 June 2000 at the Doubletree hotel, Rockville, MD) Organized by Drs. Jerry Frankenheim and Minda Lynch in response to the rapid ascent of GHB and its precursors, GBL and 1,4-butanediol, as public health concerns.